18
Thu, Jul
2 New Articles

TechTip: DCL-* Conversion from Fixed-Format H-, F-, and D-specs

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

There are a many differences between fixed-format and DCL-*. Some subtle, some not so subtle, and a few that are downright painful.

 

Whether you're free-handing (pun intended) new free-format DCL-* specs or converting existing fixed-format H-, F-, or D-specs to free, this article shares what I learned while writing a free automated conversion tool to generate free-format DCL-* statements from fixed-format.

 

If you plan to write in /free, you may wish to keep this article handy as a quick reference of what you need to do to compile.

 

Check OS Version and PTF

DSPDTAARA DTAARA(QUSRSYS/QSS1MRI)The first two positions of the value must be V7.

 

DSPPTF LICPGM(5770WDS) SELECT(SI51094)Any CUM upgrades after January 2015 will have this PTF (or the superseding PTF) included.

 

If you do not have both the OS and PTF, please enjoy the rest of the article for future reference.

 

Turn SEU Syntax-Checking Off

Please note the new H, F, and D DCL-*free source code lines will reverse image as invalid in SEU. (I am still mad about %SCANRPL not being supported in V6R1 SEU). I turn the SEU syntax-checker off (F13 and N for syntax checking) and keep going.  

 

CLASS, DATFMT, TIMFMT, and PROCPTR Convert to Data Type Extensions

Notice the fixed-format D-spec keyword DATFMT is not used in the dcl-s statement. The extension (*ISO) is now part of the date data type.

 

Datfmt Date Format

D wedate         s               d   datfmt(*iso-)          

dcl-s wedate   date(*iso-);

 

D wkmdy           s               d   datfmt(*mdy/)    

dcl-s wkmdy date(*mdy/);

 

 

Timfmt Time Format

D TIMER           s               T   TIMfmt(*iso)

dcl-s TIMER time(*iso);

 

Procptr Procedure Pointer

The asterisk (*) signifying a pointer data type is replaced with word POINTER data type. The PROCPTR keyword is an extension (*PROC) of the data type.  

                                    

D CANCLHDLRPTR   S               *   PROCPTR                

D                                     INZ(%PADDR('CANCLHDLR'))

 

dcl-s CANCLHDLRPTR pointer(*proc) inz(%paddr('CANCLHDLR'));      

 

 

CLASS Java Object

The class word is dropped entirely and is now part of the OBJECT datatype extension. Notice the keyword data has been reformatted to fit in 74 characters. More on continuation rules later.

 

D nformulaevaluator...                                                    

D                 s               o   class(*java: 'org.apache.poi.ss.us+

D                                     ermodel.FormulaEvaluator' )    

  

dcl-s nformulaevaluator object                          

(*java: 'org.apache.poi.ss.usermodel.FormulaEvaluator' );

 

 

VARYING Keyword Removed and the VARCHAR Data Type Is Used

D BuildContin     s           200a   varying

dcl-s BuildContin varchar(200);

 

*NEXT Is Removed if the Overlay Keyword Is the Data Structure Name

I had concerns about this one at first and took a little while to test and verify. The *NEXT extension is truly redundant if overlaying the data structure name.

 

The *NEXT keyword is still valid if you are overlaying a data structure subfield. Notice line 27 overlays the data structure name and line 29 overlays a subfield.

 

0024.00 D nestds         ds           100                        

0025.00 D aa1                     1     4a   dim(dimsize)        

0026.00 D aa2                           4a   overlay(nestds:1)    

0027.00 D aa3                           4a   overlay(nestds:*next)

0028.00 D bb1                           1a   overlay(aa1:1)      

0029.00 d cc2                           2a   overlay(aa1:*next)  

 

 

After conversion, the *NEXT at line 27 is removed. The *NEXT at line 29 remains in place.

 

 

0024.00   dcl-ds nestds len(100);          

0025.00   aa1 char(4) dim(dimsize) pos(1);

0026.00   aa2 char(4) pos(1);            

0027.00   aa3 char(4);                    

0028.00   bb1 char(1) overlay(aa1:1);    

0029.00   cc2 char(2) overlay(aa1:*next);

0030.00   end-ds;                          

 

Also note line 26 changed from OVERLAY(nestds:1) to POS(1) notation as the field was overlaying the Data Structure name.

 

DS LEN Is Not Allowed with Extname

This one to me is like the enforced correction of an old wrong. I work on a lot of code with ambiguous code, like the DSNAME has a length and an EXTNAME.

 

D DSNAME         E DS         1000   EXTNAME(FILENAME) .

 

The record length of FILENAME is not 1000. After conversion, the statement will look like this:

 

dcl-ds DSNAME len(1000) extname('FILENAME') end-ds;      

 

And your compile listing will look like this:

 

*RNF3529 20 a     000010

 

Extname Keyword is not allowed for a program-described data structure; keyword is ignored.      

 

Your solution is to remove the len(1000) and either change the program to work with the correct length or change the format of FILENAME to equal the data structure length required.    

            

+ or - Lengths Are Now Part of the Data Type Extension, Packed(1: +2)

This change is a much better read than overloading the To/Length field in fixed-format.

 

D NextStepFlg     s         -   9   like(srUserStat)        

dcl-s NextStepFlg like(sruserstat:-9);

 

Data Areas

I can only imagine an IBM memo came down from on high to the compiler writers that said, "Remove the *VAR keyword and make them remember all these syntactical nitpicking rules." (More about this memo when we get to the DCL-F specs usage keyword.) And to be clear, this is not the same memo that said "Cripple the loyal vast majority using SEU."

 

Data Area Names Will Be Quoted and Uppercased

Now, with data areas, you have to remember where to put a quote or uppercase. If your data area name is a not a variable or constant, you now must quote and uppercase the dtaara keyword name.

 

dcl-ds ScreenFieldDS extname(JCRFFDF:AA) end-ds; is not valid unless JCRFFDF and AA are a constant or a defined field name.



dcl-ds ScreenFieldDS extname('JCRFFDF':'AA') end-ds; // with quotes around each piece is how you have to do it now.

 

Data Area *VAR Modifier Is Removed

If your data area name is a variable name, do not put quotes around it.

  

UDS Requires DTAARA{name) {*AUTO}

Fixed-format allowed IN and OUT opcodes with UDS. If you are using these opcodes, change the *auto keyword to *userctl so these codes will still work

 

Quick Reference

Table 1 shows fixed-format keywords on the left and /free equivalents on the right.

 

Fixed-Format and Free-Format Data Area Keywords

Fixed-Format Keywords

/free Equivalents

Dtaara(*VAR : runtimeDA)

dtaara(runtimeDA) ;

Dtaara(runtimeDA)

dtaara('RUNTIMEDA');

uds dtaara(TESTX73)

dtaara(*auto: 'TESTX73');

uds dtaara(*lda)

dtaara(*auto: *LDA);

Uds

dtaara(*auto);

uds dtaara

dtaara(*auto);          

Dtaara

Dtaara;

 

Continuation Lines (+ and -) Must Be Reformatted as Keywords Are Expanded or Removed

I must confess to never having used the minus sign (–) continuation character, which was interesting as the continuation character can make a big difference when the definition space expanded from 37 to 74 characters.

 

In case I'm not the only person on the planet who didn't know the difference, the plus sign (+) keeps spaces only before it.

 

aa char(10) inz('A+

         B');

Results in aa='AB'

 

The minus sign (-) preserves all the spaces before and after it.

 

aa char(10) inz('A -

         B');

Results in aa='A       B'

 

 

Please be aware I had to reformat your inz and constant values to allow for the number of spaces available in free-format. If you are manually converting, your plus sign continuations will be OK. You will have to move the characters after the minus sign to keep spacing correct.

 

 

D c@hars         c           const('abcdefghijklmnopqrstuvwxyzABC-

D                                     DEFGHIJKLMNOPQRSTUVWXYZ<>?:;!@#$%¢&;*-

D                                    ()-_=+¬¦{}\|<>,./?`~')              

 

dcl-c c@hars const('abcdefghzjklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXY-

Z<>?:;!@#$%¢&;*()-_=+¬¦{}\|<>,./?`~');

 

                                

Remove All /free and /end-free Statements

Yeah! Love it. We do not need these statements any more. Aesthetics aside, mix and match fixed and free as you wish.

 

Remove All PR Prototypes for Procedures Defined Internally

Here is even more to love. If the procedure interface is defined internally, meaning the procedure is inside this program source, you do not need to include the redundant PR definition. This includes the *entry parameters prototype.

 

This is the suggested *Entry procedure interface (with no PR):

//---*ENTRY--------

dcl-pi *n;

parm fields

end-pi;

 

You will need to have a dftactgrp keyword in your H-specsorry, I meant CTL-OPT statementif you remove the *entry PR. Here is a standard CTL-OPT statement I use for general programming.

 

ctl-opt dftactgrp(*no) actgrp(*caller) expropts(*resdecpos)

datfmt(*iso) timfmt(*iso) option(*nodebugio: *NOUNREF);    

 

Notice the new *NOUNREF keyword in the options string. To quote the manual, "*NOUNREF indicates that unreferenced variables should not be generated into the RPG module. This can reduce program size, and if imported variables are not referenced, it can reduce the time taken to bind a module to a program or service program." I have put this keyword in all my copy books and RPGLEHSPEC dtaaras.

 

*DELETE Will Be Added to the Usage Keyword If Record Is Deleted in Main or Procedure

Frankly, I could have gone the rest of the day without the dcl-f USAGE keyword and certainly the rest of my career without the *DELETE keyword in the usage statement. Not sure how we go from a simple, single, one-keystroke U for update in the F-specs to typing out USAGE(*UPDATE:*DELETE*OUTPUT) and call that progress.

 

IBM requires a usage (*delete) keyword if the file or any record format in that file has a delete opcode in the main or F-specs inside any dcl-proc. This massively complicates the F-specs source conversion as now I have to read the entire source, looking for DELETE opcodes by file or included record formats, and figure out if the DELETE opcode is in the main or in a procedure (and keep track of the procedure names containing the delete opcodes) and where the file was declared. Ugh.

 

An inclusive cross-reference of old F-specs versus new would be as long as the article to this point.

 

I have never told anyone to read the manual. Honestly though, your best bet is to review IBM i Version 7.1 Programming - IBM Rational Development Studio for I ILE RPG Reference section 5-39.

 

Below is an excerpt from the /free conversion utility JCRHFD that can be used for quick reference. Look for the usage string.

 

From the fixed-format F-specs: File Type is Input, Update or Output single character. Designation is Primary, Secondary, and Full etc. FileAddition is the A for add. IsDelete means I found a DELETE opcode in the main or in the procedure being processed.

 

   //-------------------------------        

if FileType = 'I'                      

     and Designation = 'F'                

     and FileAddition = ' ';            

                                          

     if not (Device = 'DISK '            

       or Device = 'SEQ   '            

       or Device = 'SPECIAL');          

       string = 'usage(*input)';        

     endif;                              

                                          

   //-------------------------------    

elseif FileType = 'I'                  

     and Designation = 'F'                

     and FileAddition = 'A';            

     string = 'usage(*input: *output)';  

 

   //-------------------------------                

elseif FileType = 'U'                              

   and Designation = 'F'                            

   and FileAddition = ' ';                        

   if IsDelete;                                    

       string = 'usage(*update: *delete)';          

   else;                                            

       string = 'usage(*update)';                    

   endif;                                          

                                                      

   //-------------------------------                

elseif FileType = 'U'                              

   and Designation = 'F'                            

   and FileAddition = 'A';                        

   if IsDelete;                                    

       string = 'usage(*update: *delete: *output)';  

   else;                                            

       string = 'usage(*update: *output)';          

   endif;        

 

     //-------------------------------

   elseif FileType = 'O'              

     and Designation = ' ';          

     if not (Device = 'PRINTER');    

         string = 'usage(*output)';  

     endif;                          

                                      

 

Please note primary and secondary files will not convert to free-format.  

  

Positive Note

In my opinion, if we could ditch the usage keyword and the quote/uppercase requirements and fix the STRSEU syntax-checker, there are a couple of things I really like in the new /free. It is fun to be able to define a procedure with just DCL-PROC NAME; END-PROC.

 

Surprise Ending

The real reason I like the new /free has nothing to with the syntax but rather the IBM Rational Developer for i (RDi) Show Indentation window and the JCRCMDS JCRSDENT Show Source Indentation screen. Both tools show the new D-specs indented as structures.

 

It is easy to see the start and stop of data structures, prototypes, and procedure interfaces if they are outlined and indented.

 

An indented data structure (dcl-ds) listed in the RDI Show Indentation window is shown below in Figure 1.

 

090415RutledgeFigure 1

Figure 1: The indented data structure looks like this.

 

The DCL-PR and DCL-PI indents so nicely it is just great, as shown in Figure 2.

 

090415RutledgeFigure 2

Figure 2: And here's the indented dcl-proc and dcl-pi.

 

Free (no cost) RPG free-format source using the Free Software Foundation license for the free conversion tool is JCRHFD at www.jcrcmds.com. (That is a lot of free!)

  

Craig Rutledge

Craig Rutledge is an IBM-certified AS/400 RPG programmer currently working as a project manager in the Dalton, Georgia, carpet industry. Visit his website at www.jcrcmds.com.

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: